Routing services forward messages from a content provider to a particular device. For example, a content provider may send a request, which includes a message and identifies a particular device, to a routing service. In response to receiving the request from the content provider, the routing service may forward the message to the particular device.
Unfortunately, to use this technique, content providers must keep track of the devices to which the content provider wishes to send messages. Content providers must also update all information related to each device to which the content provider wishes to send a message. For example, a content provider may develop a publish/subscribe system that receives subscription requests from users. If an error arises while a user attempts to subscribe to receive messages from the content provider, the content provider may be unable to provide the necessary information to the routing service to send the user messages. Furthermore, the publish/subscribe system may receive unsubscribe requests from users to stop receiving messages. If an error arises while a user requests to stop receiving messages from the content provider, then the content provider may continue to send messages to the user.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.